Signal conditioning circuitry for silicon pressure sensor

A bipolar integrated silicon pressure sensor with signal conditioning circuitry, including a band-gap reference a differential amplifier, a voltage-to-current converter, and a current-controlled oscillator, is presented. The circuits were designed to suppress the influence of temperature and supply voltage variation. The signal conditioning circuitry can convert input pressure to a square waveform with a temperature coefficient of 67 ppm/ degrees C in the temperature range of 0 degrees C approximately 50 degrees C. This signal conditioning circuitry was fabricated by double-diffused bipolar technology and can be operated at up to 14 psi.<>